A distress call is received from the 1000-year-old Babylon 4 space station. Sheridan, Ivanova, Garibaldi, and Delenn go to investigate. They find some modern aliens seemingly intent on destroying them, an some ancient archival material about Valen, the beginning of the Rangers, and the last Shadow war.
Written by the architect of the Babylon 5 arc, Joe Straczynski himself, this story is part of the B5 canon. It gives an interesting insight into what happened to Sinclair after he left Babylon 5, has some good acid asides from Ivanova, and has some new aliens with a ... different ... philosophy.